I think once a week - every week is unreasonable. Firstly, whilst he's out with his mates, you're at home looking after the baby and secondly, why isn't he happy spending his time with you? I had this problem years ago when I was 22 and had my first child. BF went out every weekend, came home drunk and simply carried on with his social life as though he had no responsibilities. In all other areas he was a gem. I hated the fact that he was always so drunk and would spend all weekend nursing a sore head! Because I'd had a baby, my outlook had completely changed and I didn't want to go out. Anyway, I put it down to age and that fact that we were young and it would take some adjustment for him (I'd had nine months to prepare). I decided to hang on in there and 16 years later I can happily say we're still together with another child that came along two years after the first!! I have to say though, my patience would have run out at some point! I continuously nagged him to make his 'night out' only once a month with the ultimatum of 'your family or regular boozy nights out'. Don't give up - he'll eventually realise (as his mates all settle down in relationships) that he'd rather be at home - but don't make it easy for him.